Gas chromatography and mass spectrometry will be developed as analytical methods for the analysis of nucleic acid hydrolysates. Enzymatic hydrolysis of RNA or DNA will be followed by trimethylsilylation prior to gas chromatography. Repetitive scanning and multiple ion detection techniques will be used for identification of individual nucleosides, particularly in transfer RNA. Mass spectrometric methods will be developed for structural studies of polyoxin nucleoside antibiotics, both as the intact molecule and following chemical cleavage of the peptide moiety from the sugar. Gas chromatographic and mass spectrometric properties of N6-isopentenyladenosine and related nucleosides will be examined in order to establish a method of analysis. BIBLIOGRAPHIC REFERENCES: T. Hashizume, J. G. Liehr, and J. A. McCloskey. Electron Impact Induced Reactions of N6-(3-Methyl-2-butenyl)adenosine and Related Cytokinins. Biomed. Mass Spectrom., 3, 177 (1976). T. Azuma, K. Isono, P.F. Crain, and J.A. McCloskey. Chemical Transglycosylation of Octosyl Acid. Tetrahedron Lett., 1687 (1976).